Inside frosting of neon signs



Oct. 29, 1935. J. c. HpSTETTER ET AL 3 INSIDE FROSTING OF NEON SIGNS Filed Oct. 24, 1931 INVENTOR. JOHN C. HOSTETTEI? & ROWLAND D. sM/TH ,L @Q ATTORNEYS.

Patented Oct. 29, 1935 UNITED STATES PATENT OFFIE INSIDE FROSTING OF NEON SIGNS John 0. Hostetter and Rowland 1). Smith, corning, N. Y., assignors to Corning Glass Works, Corning, N. Y., a corporation of New York This invention relates to improvements in luminescent signs of the type commonly known as neon signs. In the manufacture of neon signs, it is common to employ clear glass tubing and bend it with the aid of local heating into various shapes whereupon the electrodes are introduced, the

tubes exhausted and then filled with one or more ases of the noble group which includes neon,

l0 argon, helium, etc. Thesignis then placed in position and current supplied to it with the result that the gas becomes luminous and forms a thread of illumination running throughout the sign letters and characters. While such signs have proven quite satisfactory, as is evidenced by their wide commercial application, they have been more or less criticized due to the fact that in some cases the light does not completely fill the tube but apparently is confined to a narrow streak of intense illumination through the center of the tube which produces glare. I An object of this invention is to improve the appearance of such signs.

Another object is to reduce the glare produced by luminescent signs.

A further object is to cause a diffusion of the I light which will give the appearance of a tube filled with luminescence.

The above and other objects may be accomplished by employing our invention which embodies the inside frosting of a sign or a portion of a sign after the tubing forming it has been bent into the desired configuration.

In the drawing;

Fig. 1 illustrates an elevational view showing a sign mounted on a cradle preparatory to frosting it.

Fig. 2 illustrates a perspective view partially in section showing a finished sign.

In carrying the invention into practice, we first select a suitable piece of cleartubing and by methods well known in the art bend it into the desired shape, for instance into the letters Gas as illustrated at ID in the drawing. The signor an individual character thereof, as the case may be, is then supported in a cradle ll having hollow shafts 12 which are supported in suitable bearings l3 and which are provided at their inner ends with nipples and flexible tubes ll joining 50 the ends of the sign Ill. The flexible tubes l4 are preferably of rubber but may be composed of any flexible material such as lead or copper which is not attacked by the frosting solution. The

outer end of one of the hollow shafts I2 is con- 65 nected through a turnable union IS with a pipeline I6 terminating in branch lines I! and I8 which are provided with valves I9 and 20. The line I1 is adapted to be connected interchangeably with a source of water and compressed air (not shown). The line l8 extends downwardly 5 into and near the bottom of a receptacle 2| which contains a frosting solution.

The outer end of the other hollow shaft 72 is connected through a turnable union. 22 with a pipe-line 23 terminating in branch lines 24 and 10 25 which are provided with valves 26 and 21. The line 24 is a waste disposal line. The line 25 extends nearly to the bottom of a closed receptacle 28 from the top of which extends a suction line 29 provided with a valve 30. 15

By closing valves l9 and 28 and opening valves 20, 21 and 30, the frosting solution will be drawn through the sign or character so as to produce a frosted surface within the glass tubing. In order toprevent the trapping of air within the 20 glass tubing and the consequent failure to frost its entire surface, it has been found necessaryto agitate it. This may be accomplished by rotating or oscillating the cradle II on its horizontal axis and for this purpose a pinion 3| is 5 secured'to one of the shafts l2 in mesh with a gear 32 which may be driven in any suitable manner such as by a hand crank 33.

when sufficient frosting solution has been drawn or forced through the sign or character 30 to completely displace the air contained therein the valve 21 isclosed and the glass is allowed to frost for a time in accordance with the usual frosting practice after which the sign or character is emptied by closing the valve 20 and open- 5 ing valves l9 and 21, the valve l-9 being vented to the open air in this case. When the sign or character is empty of frosting solution the valve 21 is closed, valve 26 is opened and sufficient hot water is passed into the line l'l to wash out the 40 sign or character and carry the residual frosting solution and rinse water through the line 24. After the sign or characterhas been completely washed out, air which may be preheated and dried if desired, is passed into the line H to dry out the glass tubing. Although the tubing if desired may be further treated by the fortifying step in accordance with the practice usually employed in bulb frosting, we have found this to be unnecessary as the strength of the relatively heavywalled tubing is not too greatly diminished if this step is omitted. It will be obvious that compressed air may be used in lieu of suction to fill and empty the sign with frosting solution by substituting a closed container for the receptacle 2| desired.

After the sign or character has been frosted, as indicated at 34, in the: manner disclosed, the electrodes are sealed into opposite ends of the tubing as indicated at 35, whereupon the sign or character is exhausted, filled with the desired gas and sealed off, after which it is ready for use.

While in the ioregoing there has been shown and described the preferred embodiment of our invention it is to be understood that minor changes in the details of construction, combination-and arrangement of parts may be resorted to without departing from the spirit and scopeglass tube bent into the desired configuration and uniformly frosted on its interior, electrodes sealed in opposite ends of the tube and gas within the tube through which electrical discharge between the electrodes takes place.

JOHN C.-HO8TEI'1ER. ROWLAND D. SMITH. 

